Winnow
WINNOW, verb transitive [Latin , a fan.]
1. To separate and drive off the chaff from grain by means of wind. Grain is winnowed by a fan, or by a machine, or by pouring it out of a vessel in a current of air.
2. To fan; to beat as with wings.
3. To examine; to sift for the purpose of separating falsehood from truth.
4. To separate, as the bad from the good.
WINNOW, verb intransitive To separate chaff from corn.